Reign of Yuan Dynasty
Although founded by the Mongolian ethnic minority, the general ruling mode of the Yuan Dynasty still followed the political pattern of the previous regimes set up by Han people. Ruling for more than 30 years, Kublai Khan, or rather Emperor Shizu of Yuan was an advocator of Han's ruling system. His reign was regarded as the most prosperous period of the Yuan Dynasty. However, due to the incompetence of later emperors, the Yuan court became corrupt which led to the end of the regime.
Reign of Kublai Khan
In economy, Kublai Khan focused much attention on the development of agriculture and water conservancy construction. In the process of Mongolian's conquest, the agriculture of the northern areas of China was seriously damaged. In the early period of Kublai Khan's reign, the agricultural production gradually recovered and the cultivation areas were greatly increased. Certain achievements were also made in water conservancy and special departments of water treatment were set up. The Yellow River was treated for three times while two new canals were constructed in its capital Dadu (currently Beijing) and Shandong Province for irrigation.
What is more, in Kublai Khan's reign, the control and exploitation towards the border areas were greatly promoted, which enhanced the cultural and economical ties between people in ethnic minorities in border areas and inland regions. At that time, there were a total of eleven 'Xingsheng's making up the whole nation, including the newly unified Yunnan, Tibet, Taiwan and Penghu areas. Still in the frontier areas such as the northwest Xinjiang and the northeast Heilongjiang regions were developed well under the powerful governing of the central court. The unified nation promoted people's inter-regional movement thus the communication between different ethnic minorities and regions were increasingly enhanced. All this consolidated the development of the Yuan Dynasty as a unified multi-ethnic country.
Reign of Later Emperors
None of the late emperors of Yuan were as competent and as ambitious as Kublai Khan, hence the Yuan Dynasty began to decline. After Kublai Khan died, Emperor Chengzong ascended the throne. Because he was a conservative and weak-minded emperor, the society of the Yuan Dynasty failed to progress in his reign. Emperor Chengzong was succeeded by Emperor Wuzhong who was more incompetent in dealing with the state affairs. Unfortunately, years of famine broke out in Wuzong's reign which sped up the decline of the Yuan Dynasty. Until the reign of Emperor Renzong, a series of renovation policies were carried out including laying off some redundant officials and reemploying the once-interrupted imperial examination. However, good things did not last. Some powerful ministers dominated the court, which interrupted the renovation. There were also several emperors after Emperor Renzong trying to improve the court order, but all were in vain. Starting from Emperor Taiding, the power struggle within the ruling class became more and more intense, let alone the severe ethnic contradiction caused by the 'Four Class System'. Since then, the Yuan Dynasty could not stop its step to decline.